The Broken Combine is a vehicle like the normal Combine.
When you first arrive to the English Countryside, you'll have a Broken Combine that needs 5 Vehicle Parts to be a normal and new Combine. After the 5 Parts, you'll have the English Combine.
This vehicle works exactly like the normal Combine, so you can plow, harvest and seed.
NOTE: Purchasing this for your Home Farm or Lighthouse Cove Farm will need 39 more Vehicle Parts to be built instead of 5.